It may be said that with respect to information processing and communication environment, mankind realized a highly convenient environment never realized from historic times with development of computer technology at present. In other words, it can be said that a stimulating perfect good field for brain was realized. On the other hand, with respect to an environment for body, it cannot be said that modern society is always a good environment due to increase of pollution materials, floating of dust or infectious bacteria in air, etc.
A clean environment exists for large-scale semiconductor manufacture conventionally. However, the clean environment is only for professional use, i.e., for industry. No clean environment for consumer used for general houses has been introduced. Once in the world of computers, personal computers flourished, carrying the banner for “Computer for the rest of us” and drawing the line between the personal computers and the large-scale computer main frame for business. Like this, while the importance of environment increases in twenty-first century, it may be hoped that “clean environment version” of personal computers appears. In fact, a personal clean space, which is the counterpart of just “main frame” as large-scale clean room with the high performance realized in long time ago, will surely become important in the future not only for pure consumer but also for scenes such as hospitals, institutions for the aged, etc. in which it is important to avoid risk of infection. Bringing a clean space in the world of consumer will realize “for all of us” beyond “the rest of us” and is very important. However, at present it is not easy to introduce a personal clean environment into a general living environment, drawing the line between the personal clean environment and the conventional clean room, as described later. It is a matter of great urgency for us to establish the scalable high performance “air environment controlling apparatus” (which can eliminate all airborne matters from dust to microbes, and conversely speaking, control desired matter in an appropriate concentration) corresponding to a vacuum chamber (with respect to controlling gas molecules enclosed in the chamber) that made possible development of science, made industrial technology sophisticated and played a big part. With this, it becomes possible to develop bioscience and make medical treatment and nursing industrial technology high. Particularly, it will become more important in the future to control an air environment for the problem of PM 2.5, further, a microbial environment in a living space.
Let's see conventional general houses. FIG. 1 is a perspective view showing an example. FIG. 2 is a drawing showing a cross section of another example of conventional general houses.
As shown in FIG. 1, a house 500 is provided with a living part 505 surrounded by walls 501 on a base 504 and invasion of wind, rain, dust, etc. is prevented by being formed of a roof 503 so as to cover the upper part of the living part 505. At least one of the walls 501 has a window 502. Furthermore, as shown in FIG. 2, the house 500 is provided with the living part 505 surrounded by the walls 501 on the base 504 and a roof 503 is provided on the upper part of the living part 505 so as to cover the whole of the living part 505 as the same as mentioned above. Two spaces, i.e., a space 507b between the roof and the ceiling and a space 507a under the floor are provided between the living part 505 and the roof 503 and between the living part 505 and the base 504, respectively. These spaces play a role of, for example, insulation, introduction of outside air, etc.
The living part 505 is constructed by being surrounded by the walls 501. For example, the living part 505 is constructed by being surrounded by the walls 501 as lateral walls, ceiling walls, floor walls, etc. The living part 505 is divided, for example, by a partition wall 501d provided inside the living part 505, etc. to form a room 505a, a hallway 505b, etc. The space surrounded by the room 505a is a living space 506. The partition wall 501d has a door 508. The living space 506 is partitioned as wide as possible. Outside air is introduced into the living space 506 from the outer space through the space 507a under the floor, the space 507b between the roof and the ceiling, etc. and the inside of the room and the outer space communicates by air.
Walls for partitioning the living space is now explained. FIG. 3 is a perspective view showing an example of construction of a wall of a conventional general house. FIG. 4 and FIG. 5 are perspective views showing examples of construction of walls of apartment houses, buildings, etc.
As shown in FIG. 3, the wall 501 is reinforced by providing an inner wall 501a and an outer wall 501b facing each other apart a constant distance and by providing an intermediate pillar 508 in a space sandwiched by the inner wall 501a and the outer wall 501b and the rest space is almost densely filled with insulator 509. Because the wall 501 has such a structure, its weight can be held down. Also, because the structure of the wall 501 is the filled structure, the strength of the wall 501 can be kept while improving the performance of insulation and soundproof. Furthermore, as shown in FIG. 4, in another example of the wall 501, the insulator 509 is densely filled in a space sandwiched between the outer wall 501b constructed by concrete having inside a steel rib 510 and the inner wall 501a on which a wallpaper 501c is provided. Also, as shown in FIG. 5, in this example, the wall 501 having the steel rib 510 is provided on a floor slab 511 and the wall 501 has a filled structure. As described above, the walls of conventional architectures such as houses, apartment houses, buildings, etc. have generally a filled structure such as a solid wall. On the other hand, a thin inner wall may be provided for the thin outer wall in houses etc. to hold down the weight of a wall made of a single wall. However, heretofore, in order to obtain the strength of the wall and enhance the effect of insulation, soundproof, etc., reinforcement, insulation, etc. are densely filled. Finally, the wall has frequently a multilayer structure and has essentially a filled structure. Conventional hollow walls mainly aim to reduce the weight of the wall as light as possible to reduce the total weight of the upstairs in wooden houses such as tow-story houses, three-story houses, for example. There has been no attempt to hollow the wall and positively use the hollowness to improve cleanliness of the room adjacent to the wall.
Under the circumstances, Ministry of Land, Infrastructure and Transport has proclaimed the promotion of houses utilizing the nature of area to take a step forward from general situation of conventional houses described above. The Forestry Agency also has begun to support building of houses utilizing wood of the concerned area and steered for energy saving houses and long life excellent houses. Genuine walls and Japanese style tiles adequate for climate in Japan and cultivated in history for over one thousand and hundreds of years are positively revaluated. As a standard of long life excellent houses introduced by an accumulation of technology, earthquake-resistance, deterioration-resistance, energy saving the performance and maintenance and keeping measure are mentioned (for example, see non-patent literature 1). According to this, the concept of energy saving and smart houses is presented by respective house makers of Japan (see, for example, non-patent literatures 2 and 3). On the other hand, the importance of houses that can make wind path is pointed out.
However, the concept of smart houses directs mainly to energy management targeting mainly electric power. And the concept of improving wind path lies mainly only presentation in view of air conditioning such as cool breeze control.
Furthermore, the importance of clean environment is increasing more and more in general houses, offices in a building, etc. and the demand for clean environment rises. Its reason is as follows. To take measures against not only pollinosis but also an epidemic of influenza, even if source materials are brought into the house, it is highly necessary to remove and control the source materials.
However, as understood from the above situation, it is not easy to improve the performance of a room revolutionary and essentially. Although it is desired in principle to increase the volume ratio of a room that is a space for living/activity to the whole construction while keeping the rigidity of the room, there exists an air current between the room and the outer space, i.e., an air passage as a mass flow between the inside and outside in conventional constructions. Therefore, cleanliness of the room is basically in equilibrium to that of the outer space. As a result, cleanliness of the room regrettably stays equivalent to that of the outer space or slightly high cleanliness due to removal of exhaust gas, smoke, dust, etc.
Under the circumstances, the above mentioned smart house framework that is an excellent technical idea is apt to be thought dummy. As a result, it is very difficult to improve quality of life. However, it is predicted that the necessity of clean environment increases more and more in Japan in which the ratio of aged persons is increasing and further in each country in the world in the near future and the clean environment is to be urgently introduced.
For example, especially the number of patients suffering from allergy such as asthma, atopic dermatitis, etc. is increasing rapidly in recent years. Allergic asthma due to inflammation of a respiratory tract is considered to be caused by various stimulus such as antigen, germs, etc. that invade from the outside. With respect to the cause of asthma, the possibility that weakness of the barrier function of epithelium cells of the respiratory tract relates to it. The barrier function of the epithelium cells of the respiratory tract is determined by the three dimensional structure of cells and the function of protein connecting cells. If the barrier function is weak, substances are easy to invade from the outside than usual and an inflammation reaction of the epithelium cells of the respiratory tract becomes strong more and more. As the epithelium cells of the respiratory tract of a patient whose barrier function is weak are damaged by frequent infection of virus or inflammation and their restoration is not normally carried out, it is considered that there is a possibility of malfunction of immunity, appearance of irritation to environment matter, and a structure change of the respiratory tract by chronic continuous inflammation of the respiratory tract. As described above, it is important for patients suffering from asthma allergic inflammation of the respiratory tract to suppress various stimulation such as antigen and microbes invading from the outside not only in hospital but also in general life at home as much as possible. In order to realize this, it is necessary to greatly clean air in a living environment. However, a huge sum of money is necessary to attain a goal with existing technology. For example, a clean room of US209D class 1 (ISO class 3) that is used in semiconductor processing, etc. is a highly clean space called a super clean room. It takes a huge sum of money to construct and maintain the system. Such a clean environment is suitable for a medical environment and is expected to prevent air infectious disease such as influenza, etc., to suppress pollinosis, to recover damaged respiratory organs during sleeping in night, etc. It is very important to introduce a clean space into a room of a house, a daily space in which a patient having such a disease lives, to switch on or off the clean environment voluntarily, and further to change on state and off state in a short time scale. If they are realized, the value is very high. However, it is regret to say that they are now impossible.
Further, in recent years, it is an urgent subject to take preventive measures against the spread of pollinosis and an epidemic of SARS or new type influenza and care the environmental weak such as babies and infants, aged persons, etc. Also, recently, the importance of microbe science and the control of microbe and its living environment is recognized more and more (for example, see non-patent literatures 4-6). It becomes important more and more to control not only airborne inorganic and organic dust but also the air environment including a microbial environment in the living space, and it is an urgent subject to realize technology and apparatus that can embodies them.
In such a situation, in order to achieve an aim to improve cleanliness of the living space, it is considered to introduce a so-called clean room. In other words, as described above, in general houses, a room, which is a living space, is formed by surrounding a space with walls, and using the room as the first stage structure, one more nesting room is built in it. With this, for at least the concerned nesting internal space to be improved its cleanliness, it is possible to realize improvement of its cleanliness by existing technology by introducing the construction of the usual clean room.
FIG. 6 is a substitute picture for a drawing showing a conventional typical clean room. FIG. 7 is a cross-sectional view showing the structure of the clean room. As shown in FIG. 6 and FIG. 7, the clean room 600 is a clean room provided with double rooms in which an existing construction 601 is provided as the first stage space and a working room 602 that is a clean room is provided inside the construction 601 as the second stage space in a nesting structure. The working room 602 forms a space without pillars inside by securing a suspended base 604 from a ceiling 603a that is the surface of a roof 603 on the side of the internal space of the construction 601 and providing reinforcements on the ceiling 606 of the working room 602. A fan filter unit (hereafter referred to FFU as necessary) 605 is provided on the ceiling 606 of the working room 602. Outside air absorbed from an absorption opening 607 and filtered by the FFU 605 is introduced into the working room 602 that is a clean room from an introduction opening 608. With this, the pressure inside the working room 602 is positive relative to the outside, and air introduced inside the working room 602 from the FFU 605 leaks together with dust inside the room from an exhaust opening 609 to the outside with a relatively low pressure, so that a highly clean environment of about class 1 to 100 is kept inside the working room 602. As described above, the ceiling and the lateral walls on every side of the clean room 600 have a double structure. Although not illustrated here, a higher clean room for semiconductors may make the floor as a double structure and realize higher cleanliness by a laminar flow and at the same time make it possible to place piping or a maintenance space under the floor. In this case, in a parallelepiped room forming the working room 602, all of the six faces of the parallelepiped has a double structure. In the conventional clean room, there exists a huge space between the outside (the first stage) room and the inside (the second stage) room. For the first stage room, there is a large loss of the area and/or volume. However, it is a usual way to use the space between the first stage room and the second stage room as a maintenance space and compensate the loss of the area and/or volume.
As described above, in the conventional clean room, a working room that becomes a clean space is constructed inside the internal space of the construction in a nesting structure. Therefore, there occurs an additional space that persons can enter between the wall of the construction and the wall of the working room. For example, for industry such as a semiconductor factory etc., i.e., for professional use, the space is effectively used as a maintenance space and a working space. However, it is very difficult and not practical to apply the structure of the conventional clean room for consumer use and introduce into a private house or a room of a building to improve cleanliness. Its reason is as follows. If the conventional structure of the clean room is introduced into a general house, the volume ratio of a life/activity space to the whole construction is markedly reduced. For this, considering the situation in Japan that a room of the house is cramp, it is practically impossible to introduce the conventional structure of the clean room into a room of a private house and a building.
Examples of a future house represented by the above smart houses correspond to a simple single structure without a nesting structure that is a double structure constructing a room inside another room like the existing clean room from the aspect of structure. The importance of a clean environment increases more and more in general houses, offices in a building, etc. having only single structure walls as described above. In addition, further difficulty of introducing the above conventional clean room structure into a room of private houses or buildings is that there occurs a pressure difference between the room that has introduced a clean room structure to improve cleanliness and other rooms around the room. This results in a situation that air including dust always leaks from the cleaned room around the room. It seems to be that emission of air inside the room to the outer space does not matter particularly. However, in Japan having the four seasons exhaust of air inside a room to the outer space in summer and winter but spring and autumn means to absorb the same quantity of air from the outer space, so that the cost of keeping room temperature by cooling and heating becomes comparatively high and it becomes difficult to maintain a clean environment. Actually, there exist no general houses with a pressure difference between rooms or between a room and a hallway etc. in the world including Japan. Therefore, it is very difficult to introduce existing clean room technology to incorporate a clean environment into a general house.
Especially, in clean rooms aiming application to industry, there are four general rules. And by obeying the rules a highly clean environment is realized. The four general rules are firstly not bringing into, secondly not generating, thirdly not depositing and fourthly removing.
That is, the first “not bringing into” means that when entering a clean room, for example, materials and equipment are to be brought into the clean room after cleaning them, pressure inside the room is to be controlled, i.e., an air current from the inside to the outside of the room is to be kept, movement of persons in the room is to be accompanied with an air shower, etc. The second “not generating” means that when acting in a clean room, for example, a dustless wear is to be worn, materials and equipment generating easily dust are not to be used, useless movement is not to be carried out, etc. The third “not depositing” means that for example, dust is not to be accumulated by providing a curved part in the junction between the wall and the floor of the clean room, the structure is to be designed so as to be cleaned easily, the structure is to be designed so as not to have unevenness, etc. The fourth “removing” means that for example, obstruction of the air current is to be reduced as much as possible by exhausting air around dust generating parts inside the clean room. Among these general rules, the first, the third and the fourth general rules are effective guidelines directly applicable to not only general living space but also nursing homes, medical and dental treatment rooms, etc. and should be obeyed. However, with respect to obeying the second general rule, because people act essentially with common clothes that are not dust-free wears in the room of houses, hospitals, nursing homes in which persons do daily life/activity such as sleeping, relaxing, working, laboring, etc. and generation of dust inside the room is a very natural result of the daily life and activity, it is practically impossible to suppress it due to direct opposition to improvement of the quality of life. From this, it is fully understood that it is almost completely unreasonable to apply the existing clean room technology simply to rooms of general houses, sickrooms, etc.
The fact that the conventional clean room needs the second general rules, i.e., the conventional clean room is weak in dust generated inside results from that an FFU attached to the clean room filters outside air but never removes dust generated inside. That is, the principle of the existing clean room is based on that clean air obtained by filtering outside air through the FFU is introduced into the clean room, thereby the concentration of dust existing in the clean room is “relatively diluted” by a contribution of the volume of the clean air and resultantly cleanliness inside the clean room is improved. That is, it only improves cleanliness in a very passive way with respect to dust generated inside because the existing clean room does not actively remove dust generated inside. In such a passive way, dust is, so to speak, “still on the loose” in rooms of a general house and a hospital or working rooms of a painting factory in which dust is inevitably generated inside and it is inevitable to exhaust dust together with gases inside and therefore it is quite difficult to improve cleanliness. Furthermore, it is needless to say that such exhaustion causes the outside a lot of trouble. In the sense, the conventional clean room is based on the tacit assumption that the outer space exists as an infinite dump and is not compatible with the twenty first century environmental view of the world that one must act on the understanding that even the earth is a finite system due to rapid expansion of human activity. It is very important to realize a clean environment self-contained without causing the outside a trouble, recognizing that the earth is a finite system.
Under the circumstances, with respect to improvement of cleanliness that is a subject of the conventional clean room, the present inventors proposed a 100% circulation feedback system to rapidly improve cleanliness of a clean room and demonstrated its effectiveness. The 100% circulation feedback system is configured so that an airtight gas flow path for introducing air flowing from a dust filter to an absorption opening of the dust filter is used as a feedback gas flow path and all of gases flowing out flow to an entrance of the dust filter through the feedback gas flow path (see, for example, patent literatures 1, 2 and non-patent literatures 7, 8).
However, all of these clean systems function only after being placed in a room provided in advance. Although cleanliness of these clean systems much improves compared with the conventional clean room shown in FIG. 7, it is used as the so-called desk top type to be used on the desk inside the room. This clean system has “a nesting structure” that it is placed inside the existing structure. Therefore, even though this clean system is scaled up, there still remains the problem that the volume ratio of life/activity space to the whole construction reduces markedly due to “the nesting structure” described above.
As described above, there exists much need for cleaning a room without changing so much from the general private room. That is, it is desired that the form like the clean room for industry is not adopted and the inside of the room is cleaned while avoiding reduction of the living space due to the nesting structure. Under such a need, as available means and the next best thing, the so-called air cleaning device is introduced into rooms of a house, offices of a building, etc. that are daily space and causative agents are removed. However, the conventional room is “a semiopen system” in which the outside space and the room are not completely separated. Or in most of the conventional room, “the semiopen system” picture is a good approximation, taking into consideration the flow rate of the air cleaning device and the ventilation rate of the room. That is, most of air inside the room is changed until the time that dust inside the room is reduced to 1/e (e is a base of a natural logarithm) by the air cleaning device. Furthermore, it is difficult to say that generation of an air current upon opening and shutting of the doorway is optimized. Therefore, the effect of the air cleaning device is limited. Under the circumstances, it is necessary for the environmental weak including persons suffering from the so-called pollinosis and asthma or the drop of the immunity in the situation that needs dialysis etc. to realize a space of higher cleanliness for example, a space with less dust, germs, odor, etc. in future in order to maintain the high quality of life. In order to form such a space, air cleaning by the conventional air cleaning device etc. is insufficient. As described above, although the air cleaning device etc. are surely introduced into the market at present, the home living environment of a quantitative clean environment is not realized at all. In order to cope with medical treatment for the aged, an immunodeficiency disease, etc., it is desired to use a germ-free room (US209D class 100) and further a space and a living environment with a cleanliness of class 1 as needed, while they do not feel at all that they are inside a mechanical-sounding clean room, and for example, the room has almost usual pure Japanese style appearance.
However, it is impossible to realize such a room.